| Sumario: | The competence between organic anions (oxalate and malate) with orthophosphate for binding places in acidic and calcareous tropical soils was studied. The experiments were performed, combining the presence of the carboxilicacids with previous and/or simultaneous additions of phosphate.
The results indicated that: i) oxalate and malate were more specifically adsorbed to soil than phosphate, i) the rep!acement of phosphate by the organic anion was not a simple competition, so that it was affected by the order of addition and the substrate concentration, iüi) oxalate's ability to desorb orthophosphate is higher than malate The possible adsorption and exchange (competition) reactions which occur between orthophosphate and the organic anions essayed are presented.
|
|---|